Space bar line lock and escapement interlock mechanism



June 1965 T. N. MADISON ETAL 3,190,429

SPACE BAR LINE LOCK AND ESCAPEMENT INTERLOCK MECHANISM Filed Jan. 28,1963 INVENTORS THEODORE N. MADISON LUDWICK sz M, 3 BY a ATTORNEYS UnitedStates Patent SPACE BAR LINE LOCK AND ESCAPEMENT INTERLUCK IVECHANHSMTheodore N. Madison, Thompsonville, and Lndwick Szeluga, Wapping, Conn,assignors to Royal McBee gorporation, New York, N.Y., a corporation ofNew ork Filed Jan. 28, 1963, Ser. No. 254,292 Claims. (Cl. 197108) Thisinvention relates to a mechanism in an electric Writing machine, suchas, for example, a typewriter, whereby a plurality of actions may bepowered, using a carriage return draw band as a source of power. Moreparticularly the invention relates to escapement line lock and space barlock operating mechanism all powered by a carriage return drawband.

' Certain models of electric typewriters are characterized by anescapement mechanism which includes a rotatable disk carrying aplurality of movable stops which are selectively movable so as to engagean abutment member upon actuation of a key lever or the space bar. Sucha mechanism is disclosed in US. Patent 3,045,798. If during carriagereturn a key lever or the space bar were depressed, an escapement stopwould be selected and would engage the abutment with possible damage tothe escapement mechanism. These machines also usually include line lockand space bar lock devices that are driven in various Ways uponactuation of the carriage return lever in order to lock out thekeyboard. Devices of this general nature are well known in the art andmay be such as disclosed in Hart 2,202,415 (a line lock comprising apivotable stop plate 62 operated through a link 59 by a lever or crank52) and such as Helmond 1,864,540 (a space bar lock comprising a spacebar 21, levers 22, arm 68 and link 31). It occasionally happens,particularly where a very fast typist is operating the machine, thatthese locking mechanisms do not react fast enough to preclude a keylever or space bar actuation immediately after operation of the carriagereturn key so that damage to I r the escapement is possible. It isaccordingly an object of this invention to provide mechanism of theabove nature that precludes such escapement damage. It is another objectof the invention to provide such a mechanism that is powered by .thecarriage return drawband.

Other objects will be in part apparent and in part pointed outhereinafter.

In the drawing wherein we have shown a preferred embodiment of theinvention and wherein similar reference characters refer to similarparts throughout the several views:

FIGURE 1 is a fragmentary top plan view of the mechanism;

FIGURE 2 is a fragmentary section taken along the line 22 of FIGURE 1;and

FIGURE 3 is a fragmentary isometric view of a portion of the mechanism.

As shown in FIGURE 1 a portion of the machine frame is indicated at 10extending through and secured to which is a shoulder screw 11. A lever,generally indicated at 12 is rockably mounted on screw 11 and includesan arm 13 through which screw 11 extends. A bushing 14 (FIGURE 2) ismounted on the screw which is held in place on the frame by a shoulder11a on the screw and a nut 15 bearing against the side of frame 10. Adrawband pulley 16 is rotatably mounted on screw 11 between the flange17 of a shroud 18 and the head 11b of the screw, the screw extendingthrough shroud flange 17. Shroud 18 also includes a short flange 19(FIGURE 2) which overlies the outer side of pulley 16, the shroud ment.

3,190,429 Patented June 22, 1965 accordingly comprising a retainer for adrawband 20 trained over the pulley. Lever 12 includes another arm 21 onwhich another pulley 22 is rotatably mounted as by a screw 23 which alsofastens another drawband shroud 24 similar to shroud 18 to arm 21, thissecond shroud acting as a retainer for drawband 20 where it trainsaround pulley 22. The ends of the drawband are respectivelyconventionally connected to the carriage (not shown) and the usualpowered winding drum (not shown) as in the well known electric Royaltypewriters- Lever 12 includes another arm 25 (FIGURE 3) through whichscrew 11 extends, this arm having an operating finger 25a notched as at25b. Another lever arm 26 is integral with and extends from lever arm25. As shown in FIGURE 1 a frame anchored spring 27 is connected tolever arm 13 and biases lever 12 counterclockwise, an ear 28 beingprovided on the lever to engage frame 10 to limit counterclockwisemovement of the lever. Thus spring 27 normally holds lever 12 in theFIGURE 1 position forcing pulley 22 upwardly against drawband 20 to forma loop L in the band.

A crank 29 is pivotally mounted on frame 10 and is biasedcounterclockwise by a spring 30 to its normal FIGURE 1 position. Crank29 carries a stud 31 adapted to be engaged by a cam surface 13a formedon lever arm 13. Crank 29 also carries a pin 32 adapted to engage atoggle link 33 which is pivotally mounted on frame 10 and which ispivotally connected to another toggle link 34 pivotally connected to anescapement disabling crank 35 which may resemble the member 20 in thesaid Lambert patent.

From the foregoing it may now be seen that at the time for carriagereturn the several parts are in their FIGURE 1 positions. Accordingly,when the carriage is released for return movement drawband 20 istensioned so that its loop L is flattened thus forcing pulley 22downwardly to rock lever 12 clockwise. Such lever movement swings arm 26to the right against a line lock crank 36 rocking the crankcounterclockwise in line lock setting direction. Crank 36 includes anarm 36a interconnected to frame 10 by a return spring 40 which holds thearm 36a against lever arm 26. Such lever movement also rocks arm 25clockwise so that the notch 25b in the end 25a thereof embraces a spacebar trigger-37 to lock it against move- Also cam 13a on lever arm 13engages stud 31 to break the toggle links 33 and 34 which rocksescapement crank 35 in escapement disabling direction. Clockwisemovement of lever 12 is limited by the engagement of an ear 38 thereonwith frame 10. At the end of carriage return the several parts resumetheir FIGURE 1 positions by virtue of spring 27 Le. spring 27 swingslever 12 counterclockwise permitting spring 30 to restore the toggle andpermitting spring 40 to swing crank 36 clockwise to its unlockingposition. Thus the several actions are powered by the drawband lendingsimplicity and efficiency to the system. Crank 36 and trigger 37, ingeneral, resemble lever or crank 52 in the said Hart patent and link 31in the said Helmond patent.

It should also be noted that when drawband 20 has imparted thereto anincrease in tension resulting from actuation of the carriage returnmechanism and before the carriage starts to move, lever arm 13 startsits clockwise movement causing the following events in the order stated:

(1) Space bar trigger 37 is locked out by arm 25;

(2) Line lock crank 36 is swung in line locking direction;

(3) The escapement crank 35 is rocked in escapement disabling direction.

Upon completion of these three events, additional tension on drawband 20initiates carriage return movement.

When the carriage has completed its return travel and comes to rest,tension on the drawband decreases to allow lever 13 to return to itsrest position under the bias 'of spring 27. In so doing events 1 -3release in reverse order, i.e. 3-1. 7 Thus in a constantrneshescapement,"as

disclosed in the above mentioned-Lambertpatent,Where the escapement isdisengagedduring carriage return, the mechanism deseribedabove assurespositive engagement and disengagement of theescapement .in relation tocarment upon line, spacing thus preventing the occurrence of I carriagebounce; 1

"Still other advantagesresult from this mechanism; Dur ing the end ofcarriage return travel where a constant mesh engagement is used, thedrawband willtemporarily loop out as 'a result of the abrupt stopping ofthe carriage;

The above described mechanism'not only reduces the loopout by'taking uplength of 'thedrawband but'also vvill instantly engage the escapementbeforeloopout takes place thus holding the carriage in proper positionl7 i Thus through the-provision of the above. described mechanism theseveralobjectsof the inventionare attained in a thoroughly efiicient andpractical manner. 1

, As other embodiments of the inventionare'possible 1. arm and movablethereby into lockingposition upon a pivotal movement ofsaid lever, I

an escapement disabling crank mounted on saidframe for movement betweenescapement disabling and enabling position, 7 I a and means operated bysaid fourth lever for moving said escapement crank to escapementdisabling position upon pivotal movement of said lever.

2. Mechanism according to claim'l wherein said second, third and-fourthlever arms are so oriented in relation to one another that said spacebar trigger, said line "lock crank and saidescapement crank are seriallyoperated in the order named.

3, Mechanism according to claim 1 wherein said means operated by said,fourth lever arm comprises a toggle connected to said'escap'ement crankand includinga cam follower and said fourthlever arm includes acamadapted 'torengage" said followerito break said toggletherebyto rocksaid escapementj crank to' escapeme nt disabling position; v

4. Mechanism according to claim lwhereinsaid lever includes apair ofstopmembers engageable with a POI! tiontof said frame to limit clockwiseand counterclockwise pivotal'movement of said lever.

and as modifications of the one disclosed may be made, I,

all without departing from the scope of the invention it is to beunderstood that the foregoing should be interpreted as illustrative andnot in a limiting sense;

We claim: I 1. A typewriter carriage return band contnolled mechanismfor operation during carriage'return movement of the typewriter carriagereturn drawband, in combination,

frame for said lever andrengagedby said, drawband, said second-- Ipulley being so located with respect to said first pulley during letterspacingmovement of the drawband so aspto form a loop therein wherebycarriage return operation of said band causes tensioning' thereof tostraighten said loop thereby causing said drawband to exert pressure. onsaid second pulley topivot' said lever andraccordingly all of saidleverarms,

spring means interconnectingone of said lever arms and;

said frame to bias said first lever arm, on which said second pulley ismounted to maintain saidloop during and at, the end of letter spacingtravel of said 7 drawband, a space bar trigger movably mounted on saidframe and operatively associatedwith the second of said lever arms,saidsecond lever arm including means to lock said trigger upon pivotalmovement of said' lever,

a line lock operating crankpivotallymounted on said v frame andoperatively' associated with said third lever, ROBERT E, PULFREY,Primary'Eraminer,

5. In a typewriter having a carriage return dr awband, the combinationof,

aframe, a

a lever pivotally mounted, on said frame,

a pulley rotatably'mounted' on said lever and engaged by a loopedportion of said drawband at the terminus of letter spacing travelof saidcarriage whereby carriage return operation of said carriage causestensioning thereof to straighten said loop and thereby exert pressure onsaid'pulley'to rock said lever,

I a line lock crank 'pivotally'mounted on said frame 'for movementbetween unlocking and locking positions,

a space bar trigger movably mountedon said frame for movement betweenspacing and non-spacing vpositions, I a

an escapement crank pivotally mounted on said frame for movement betweenescapement enabling and disablingpositions, I I V I a and meansincluding arms connected tosaid lever and movable therewith on rockingthereof when said loop is straightened to pivotnsaid line lock crankto'its locking position to, hold said space bar trigger in nonspacingposition and to pivot said escapement jcrank to escapement disablingposition.

References Cited by the Examiner UNITED STATES PATENTS 7 1,226,296 5/l7[Anderson .Q 197-,66 l r 1,784,047 12/30 Degeneraar 197-65 2,189,942 or2/40" Eibert' 19765, X 2,362,229 11/44 Yaeger 19.7l07 X 1,647,609 8/53Sagner 19766 3,018,870 '1/62 Lambert et al. 19784.3 3,045,798 7/62Lambert et al 19784 i FOREIGN PATENTS 581,662 8/33 7 Germany.

1. A TYPEWRITER CARRIAGE RETURN BAND CONTROLLED MECHANISM FOR OPERATIONDURING CARRIAGE RETURN MOVEMENT OF THE TYPEWRITER CARRIAGE RETURNDRAWBAND, IN COMBINATION, A FRAME, A LEVER COMPRISING FIRST, SECOND,THIRD AND FOURTH ARMS, MEANS TO MOUNT SAID LEVER ON SAID FRAME FORPIVOTAL MOVEMENT ONLY IN RELATION TO SAID FRAME A FIRST PULLEY ROTATABLYSUPPORTED TO SAID FRAME FOR ENGAGEMENT BY SAID DRAWBAND, A SECOND PULLEYROTATABLY MOUNTED ON SAID FIRST LEVER ARM AND MOVABLE THEREWITH UPONPIVOTAL MOVEMENT OF SAID LEVER AND ENGAGE BY SAID DRAWBAND, SAID SECONDPULLEY BEING SO LOCATED WITH RESPECT TO SAID FIRST PULLEY DURING LETTERSPACING MOVEMENT OF THE DRAWBAND SO AS TO FORM A LOOP THEREIN WHEREBYCARRIAGE RETURN OPERATION OF SAID BAND CAUSES TENTIONING THEREOF TOSTRAIGHTEN SAID LOOP THEREBY CAUSING SAID DRAWBAND TO EXERT PRESSURE ONSAID SECOND PULLEY TO PIVOT SAID LEVER AND ACCORDINGLY ALL OF SAID LEVERARMS, SPRING MEANS INTERCONNECTING ONE OF SAID LEVER ARMS AND SAID FRAMETO BIAS SAID FIRST LEVER ARM ON WHICH SAID SECOND PULLEY IS MOUNTED TOMAINTAIN SAID LOOP DURING AND AT THE END OF LETTER SPACING TRAVEL OFSAID DRAWBAND, A SPACE BAR TRIGGER MOVABLY MOUNTED ON SAID FRAME ANDOPERATIVELY ASSOCIATED WITH THE SECOND OF SAID LEVER ARMS, SAID SECONDLEVER ARM INCLUDING MEANS TO LOCK SAID TRIGGER UPON PIVOTAL MOVEMENT OFSAID LEVER, A LINE LOCK OPERATING CRANK PIVOTALLY MOUNTED ON SAID FRAMEAND OPERATIVELY ASSOCIATED WITH SAID THIRD LEVER ARM AND MOVABLE THEREBYINTO LOCKING POSITION UPON PIVOTAL MOVEMENT OF SAID LEVER, AN ESCAPEMENTDISABLING CRANK MOUNTED ON SAID FRAME FOR MOVEMENT BETWEEN ESCAPEMENTDISABLING AND ENABLING POSITION, AND MEANS OPERATED BY SAID FOURTH LEVERFOR MOVING SAID ESCAPEMENT CRANK TO ESCAPEMENT DISABLING POSITION UPONPIVOTAL MOVEMENT OF SAID LEVER.